Siddhant Bharadwaj

I am an MS in Artificial Intelligence student at Columbia University, where I study vision-language models for art under Prof. Kathleen McKeown. More broadly, I focus on: 1) VLM evaluation, finding where these models fail, from spatial reasoning and geolocalization to whether they look at the image at all, and 2) post-training strategies that close those gaps.

Previously

Outside research

When I am not programming or doing mathematics, you will find me reading, watching sitcoms, scribbling in my journal, and more often than not posting hot takes on X (formerly known as Twitter).

If you would like to collaborate or talk about one of my projects, feel free to drop a mail.

News

Publications

Papers on VLM evaluation, post-training, and medical AI.

NeurIPS 2026
Medmarks: A Comprehensive Open-Source LLM Benchmark Suite for Medical Tasks
B. Warner, ..., S. Bharadwaj, et al.
Accepted at NeurIPS 2026 Evaluations and Datasets Track (Poster)
Also at the ICML 2026 3rd Workshop on Multi-modal Foundation Models and Large Language Models for Life Sciences

An open suite of 30 medical benchmarks, used to evaluate 61 LLMs across 71 configurations.

ACCV-W 2026
Bridging the Synthetic-to-Real Gap for Few-Shot Cryo-ET Classification
S. Bharadwaj, A. Vashist, R. Singh, P. Vinodh, N. Artham, R. Jiang, X. Li, M. Xu
Accepted at the Trustworthy Foundation Models in Medical Imaging Workshop (TrustFMI) at ACCV 2026
Also at the Multimodal AI for Science and the Real World Workshop (MM4SciReal) at ACCV 2026

A trainable transformation that narrows the gap between simulated and real subtomograms at both the input and feature level, beating transfer-learning baselines in few-shot settings.

AIMLSys 2026
Robust Lightweight Deep Learning Models for Oral Cancer Screening
S. Bharadwaj*, A. Shedsale*, T. Subramanya*, M. Azfar, P. Birur, D. Pal, S. Sharma, A. Shetty, and R. Sundaresan
6th International Conference on AI–ML Systems (ACM AIMLSystems 2026)

Edge-optimised hybrid models beat large models and distillation for smartphone screening; the best MobileViTv2 reaches 87.4% sensitivity and 86.5% specificity against specialist labels.

TENCON 2026
InfUI: Harnessing Deep Learning to Bridge Eye Care Gap
S. Kotian, A. Batra, S. Bharadwaj, and J. R. H. Kumar
Accepted at IEEE TENCON 2026 (IEEE Region 10 Conference)
Preprint
Do Medical Vision Language Models Actually See? A Counterfactual Grounding Framework and Hard-Negative Contrastive Training for Visually-Reliant Medical VLMs
A. Zafar, L. K. Murali, S. Bharadwaj, A. Vashist, J. Wu
Preprint, 2026

Swapping in blank, shuffled, missing, or hard-negative images tests whether medical VLMs really use the image; our CORAL fine-tune of Qwen2.5-VL-7B gains 6.7 points in accuracy and cuts hallucination by 8.0 points.

CVPR-W 2026
Where Do Vision-Language Models Fail? World Scale Analysis for Image Country Geolocalization
S. Bharadwaj, A. Vashist, F. Aleem, S. Vyas
EarthVision Workshop at CVPR 2026

A zero-shot study of state-of-the-art VLMs predicting an image's country from ground-view imagery alone, across three geographically diverse datasets: results vary widely between models, and fine-grained geographic cues remain a weak spot.

ICLR-W 2026
Spatial Reasoning is Not a Free Lunch: A Controlled Study on LLaVA
N. Alam, L. K. Murali, S. Bharadwaj, P. Liu, T. Chung, D. Sharma, Akshata A, K. Kiran, W. Tam, B. K. S. Vegesna
ICLR 2026 Workshop (ICBINB)

A controlled LLaVA study linking weak 2D spatial reasoning to CLIP-style encoders and 1D token flattening, not just to training data.

Preprint
The Spatial Blindspot of Vision-Language Models
N. Alam, L. K. Murali, S. Bharadwaj, P. Liu, T. Chung, D. Sharma, Akshata A, K. Kiran, W. Tam, B. K. S. Vegesna
Preprint, 2026

Alternative encoder objectives and 2D positional encodings improve spatial reasoning across several benchmarks.

ICCV-W 2025
Multiscale Diagnostics of Visual Language Models
S. Bharadwaj, A. Vashist, M. Azfar, R. K. Salla, D. Verma, R. M. Amancherla
ICCV 2025 Workshop on CV4DC (Non-Archival Track)
MIDL 2025
Obscure to Observe: A Lesion-Aware MAE for Glaucoma Detection from Retinal Context
S. Bharadwaj, P. Seth, C. S. Seelamantula
Medical Imaging with Deep Learning (MIDL) 2025, Short Papers Track
ACCV-W 2024
Balanced CutMix: Enhancing Image Classification Through Curriculum Learning
M. Azfar*, S. Bharadwaj*
CV4DC Workshop at ACCV 2024
INDICON 2024
Improving Smooth GradCAM++ with Gradient Weighting Techniques
S. Bharadwaj*, M. Azfar*, A. Sasikumar
IEEE INDICON 2024 Oral Presentation
ICVGIP 2024
Adaptive Multi-Scale Document Binarisation Using Vision Mamba
M. Azfar*, S. Bharadwaj*, A. Sasikumar
ICVGIP 2024 - Tiny Papers Track

A linear-time Mamba model for document binarisation, with Difference-of-Gaussians features in the skip connections.

AICTC 2024
Vulnerability Analysis of Deep Learning Model for OCTA Image Classification
M. C. Trivedi, S. Bharadwaj
AICTC 2024

* Equal contribution

Talks

Invited talks, presentations, and demonstrations, primarily on AI for oral cancer screening and medical imaging.

Research Presentation to the Temasek Polytechnic Delegation, Singapore
TANUH (AI Centre of Excellence in Healthcare), Indian Institute of Science, Bangalore
Invited Presentation, May 2026
Aarogya Aarohan: AI-Assisted Oral Cancer Screening
IISc Open Day, Indian Institute of Science, Bangalore
Public Demonstration, 2025 and 2026
[Event]
AI Image Quality Assessment
Egyptian Youth Delegation Visit, Council Chamber, Indian Institute of Science, Bangalore
Invited Presentation, November 2025
Demonstration of the Aarogya Aarohan App
National Conference of the Foundation for Head and Neck Oncology (FHNO 2025), Hilton Bengaluru, Embassy Manyata Business Park
Demonstration, November 2025
[Event]
AI Development, AI Integration into Mobile, and AI Tool Usage on the Field
World Head and Neck Cancer Day Event, Oral Cancer Task Force Annual Meeting 2025, Golden Jubilee Hall, Indian Institute of Science, Bangalore
Invited Speaker, July 2025
[Event]
Annotation of Unstructured Radiology Data
Symposium on Digital-Twin in Oral Cancer, Mazumdar Shaw Medical Center, Narayana Health, Bangalore
Invited Talk, November 2024

Achievements

Breakthrough Concept Award - Google Cloud Agentic AI Hackathon (Prize: INR 50,000)
Second Prize - Accel x Anthropic Developers Day
Department Rank 1 - Final year of undergraduate program
Achiever Scholarship - MIT Manipal (INR 86,000 merit-based award for top 5% in department)

Writing

Occasional notes explaining ideas in deep learning and NLP from the ground up.

Breaking Down Text: How BPE Tokenization Works
Self-Attention Explained with Code